Method of electric riveting



(No Model.)

E. THOMSON. METHOD OF ELEGTRIG RIVETING.

Patented Jan. 8

Y elevation and partial section of a form of ap- .zen -oi' the United States, and a resident of ,to heat the same to the requisite temperature,

for a longer period and until the central porpressure tothe pieces to be riveted will weld l0 shows a further modification.

PATENT OFFICE.

ELIHU THOMSON, 0F LYNN, MASSACHUSETTS.

M ETHoD orv ELECTRIC RlvETaNe.

SPECIFICATION forming part of Letters P i Application filed October 12, 1888.

To all whom it may concern/.fy

Be it known that I, ELIHU THOMSON, a citi- Lynn,l in the county of Essex and State of Massachusetts, have invented a certain new and useful Improved Method .of Electric Riveting, of which the following is a specification.

My invention consists, essentially, in a method'ot riveting by placing the rivet or rivet-blank in position in the socket .or hole designed to receive it, passing through said rivet an electric current of sufficient volume and then setting the rivet in its position by endwise pressure or other means employed in ordinary riveting` operations.

In carrying out my invention l may swage or form botlrheads after the heating ot the rivet-blank in position inthe work, or may swage or form one head only, the rivet 4having been inserted with one head ready formed. The heating ofthe rivet when in position may be carried only to the point sufficient to permit it to be set by swag-ing or heading its ends, or the current may be allowed to pass tion of the rivet, as well as the metal near thereto, is raised to a welding temperature, when the application ot' pressure expanding.t the rivetin its seat will weld the same to the l metal surrounding it, and the application of them together around the rivet. ln some cases l' may cause the electric current to iiow across from piece to piece of the parts to be riveted, as well as through the rivet itself.

Detail processes,forming'a part of my invention will be more particularly specified in the claims.

ln the accompanying drawings, forming a part of this speciiication, Figure l is a side paratus suitable for carrying outv my method of electric riveting. Fig. is a view of the rivet after the operation has been effected. Figs. 3 and -t illustrate modifications in thel manner ot' practicing the invention. Figs. 5, 6, 7, and 8 are illustrations of the work accomplished. Fig. 9 is a side elevation of an improved form of apparatus which may be used in practicing my present invention. Fig.

atent No. 396,015, dated January 8, 1889.

Serial No. 287,910. (No model.)

ln Fig. ],P P in dica-te two plates of metalsuch as boiler or sheet metal-to be secured together by means'ot' a rivet placed in a hole passing through lapped portions of the plates.

C C indicate two blocks or pieces of material adapted to conduct an electric current and made suliiciently massive to permit the current of large volume required in the operation io pass without becoming unduly heated.

The electric current required is-conveyed from any source-such, for instance, as that described in my previous patent, No. 347,140* to the blocks C C by means of cables D D', or by other means, and the blocks are insulated from one another, as indicated at l, in

order to prevent the current of the cables f rom short-circuiting around the work. Supported upon thehead S of the block C', and in electrical connection tliercwitl1,is a plunger, G, whose end is of the nature of a swaging tool or die, and which may be forced against the work by means of a screw, XY. Formed upon or attached to the block C, and in electrical connection with the source ofi current, is another receiving block or anvil, E', for one end ofthe rivet. The faces or ends of the blocks G E are in line wiihone another, and are adapted to receive the rivet Rbctween them. The contour of their swaging, :torming, or holding ends may be considerably varied, according to the special manner of securing the rivet in place' which it is desired' to employ. ln the form shown in Fig. l the end ot' G is made concave to receive and tit over the end of the rivet-blank and to operate as a means of swaging a head upon the rivetblank. The otherblock, E', is similarly formed for a similar purpose.

In employing the apparatus described the blocks or pieces G E are brought to bear upon t-he rivet or rivet-blank R, which has been previously inserted into the hole through the plates, the ends otl .said blocks receiving the ends of the rivet or rivet-blank between them. Electric current is now turned on and made to pass through the rivet or blank in sufficient volume to heat the rivet to a softened condition, after which endwise pressure or other force is applied through the plunger G-as, for instance, by- Ine'ans of screw W. This will firmly seat and expand the rivet in IOO ` ner, the rivet fitting solidly into the counterits hole, and will at the same time form heads at opposite ends of the rivet-blank, or at one end thereof only, if, as indicated in Fig. 3, a rivet with a head already formed has been inserted into the hole previously to the rivet ing operation.

i f .Fig Z'illustrates the condition of things at ter the current has heated the metal to the,

` 'desired temperature.

Fig. 4 simply illustrates the fact that two plungers, G G', might be employed and moved in opposite directions or toward the riveto blank R after the blank issuficiently heated.

This figure also shows that the holes punched or bored in the plates may be countersunk, so that the riveted heads `may not protrude from the plates.

Fig. 5 shows two plates riveted in this mansiink holes, as shown at h h.

- A valuable effect, (illustrated in Fig. 6,) not possiblein other processes, may be obtained 3o in my method of riveting by continuing the heating of the rivet-blank placed inthe hole 'for some moments longer than is necessary to raise it to a softening'temperature. By conduction the heat is carried to the portions of the plate surrounding the rivet, raising such portions toa welding temperature, and when the rivetis pushed firmly into the hole a partial Welding of therivet to the sides of the hole is effected, thus forming practically 4o solid metal for a portion'of the distance from Fig. 7 showsa similar effect, which occurs when the rivet.- heads are not forced, into Vcountersun-k holes, but are allowed to pro- 4 5 trude from the plates.

Fig. 8 shows a modification where one head ofthe rivet is allowed to protrude from the plate, the other end fitting solidly and evenly into the countersunk hole bored to receive it.

which is found useful incarrying out my improved method of` electric riveting, and which 1s an improvement over that of Fig. l, inasmnch as it can be used to force the plates to- 5 5 -gether before the current is put on and keep them together while the rivet is heated and secured in place. K K are heavy clamping-l pieces having a common bed or support, B', and one o r both provided with a screw, S. By

6o means of screw S the clamping device K K Y may be forced hard against the plates P P', as shown in the figure, thus making a firm vcontact where the metals are lapped over each Qthel# 6 5- The phmgers or formers G G are mounted in the clamp-heads, and are operated bymeans Fig. shows a modified form of apparatus` of the screw-nuts X X bearing upon levers connected to the plungers. this form of apparatus a heating electric current might be passed through the metal plates themselves at parts around the ri vetby means of the pressure pieces or clamps-K K. current would assist in raising the portion of By the use of Such 5 l the plates immediately surrounding the rivet l .to the welding temperature; but the prime object is that through the application of the pressure the plates themselves ma'y be held together during the riveting. The blocks K K may therefore be faced with mica or other.

insulator, m m".

Fig. 10 shows a modification of the just-defscribed apparatus. which is used to convey thev current to the rivet R. K2 is a heavy piece of metal, so arranged as to press against the plates P P.

Pressure is applied to piece K2 from the.

plunger by the springs s s.

It will be seen that by my improved method of electric riveting a large amount of laboris overcome and much timeis saved. The heat- 'ing of the rivet can be accomplished in a very few seconds, the time depending on the power of the electric apparatus supplying the current. lt is also obvious that the inconvenience of transporting hot rivets from the forge to the hole in the boiler or other plates is avoided in my present invention. -The superior advantage, also, of partially welding the rivet to the plate is obvious.

I have described some of the forms of apparatus that may be used for carrying out my invention; but it will be readily understood that the same method might be practiced by using other devices.

lVhile I have described the Vriveting of the blank after heating as 'being performed by means of the blocks through which current is applied to the rivet or blank, it is obvious that the invention might be practiced by withdrawingsaid blocks after the rivet has been heated to the desired degree, or by applying the current through any other means, and then heading therivets by any desired means.

l have not' herein claimed the apparatus described, as my present patent is for the novel art or process, whether practiced by means of the apparatus described or any other suitable apparatus.

lVhat I claim as my invention is- 1. The herein-described improved method of riveting, consisting in heating the rivet or rivet-blank electrically while in place, and then heading either or both ends ofthe same.

2. The herein-described method or process of riveting, consisting in making the rivet while in position a portion of a circuit carrying a heating or large volume of electric current, and then setting the rivet by any 'de- G is one of the plungers' IOO sired means, as-and for the purpose described.

3. The herein-'described method o f riveting, consisting in passing a heavy electric current through the rivet or rivet-blank while the same is in position, and then applying endpressure to the rivet to set the same.

l 4. The herein-described method of riveting, consisting in applying to opposite ends of the rivet While in position suitable metal blocks or pieces, either or both movable, including said blocks and rivet in an electric circuit carrying an electric current of large volume for the purpose of heating the rivet, and then forcing said blocks or other to set' the. rivet. l

5. The herein-described method of riveting, consisting in heating the rivet while in place byv an electric'current until it assumes a Welding temperature, and then applying pressure pieces toward one al1- l.to set the rivet in its seat and unite the sides of the same to the metal body through Whiclr it passes.

6. The herein-described methodof fastening two pieces of metal together, consisting in passing a heating electric current through a rivet or rivetfblank, passing through the pieces as Well as through the pieces of metal themselves in the neighborhood of the rivet, and applying pressure to set the rivet and Weld the pieces together.

7. The herein-described method of electric riveting,l'consisting in pressing the plates to-v gether, heating the rivet inserted through the plates by a heavy electric current flowing through the same, and applying end-pressure to the rivet to head or set the'saine.

Signed at Lynn, in the county of Essex and State of Massachusetts, this 10th day of October, A. D. 1888.

ELIHU THOMSON.

1Titnessesz CHARLES G. STONE, O'rIs K. STUART. 

